Genomes of 10 microorganisms mapped

GENETICS

Microorganisms' genomes mapped

Scientists have sequenced the genetic map of 10 infectious microorganisms - including strains of salmonella and listeria - that are among the most common causes of food-borne illnesses worldwide.

The results, released May 21, are the first to come from the 100K Pathogen Genome Project run out of UC Davis. The project aims to sequence the genomes of 100,000 bacteria and viruses that cause food-borne illnesses.

Mapping the genetic makeup of these microorganisms will help public health officials diagnose and track illnesses much faster during outbreaks. It also could help scientists discover new treatments and methods for preventing these illnesses from entering the food chain.

BIOLOGY

Enzyme tied to depression found

People who suffer major depression and aren't being treated for it have increased activity of an enzyme called telomerase, which maintains and lengthens the protective caps on the ends of chromosomes, according to research at UCSF.

The chromosomal caps, called telomeres, tend to shorten with age, and shorter telomeres are associated with a variety of diseases. Increased telomerase activity may be a sign that the body is mounting a defense against biological damage from long-term depression, the UCSF scientists said.

Their initial research is small, involving only 20 patients with major depression, plus 20 control subjects. All of the patients must have suffered depression for at least 13 years, although not necessarily consecutively, and been untreated for at least six weeks.

Sixteen of the patients were treated with sertraline, an antidepressant. Levels of telomerase were tested at the start of the study and eight weeks after starting treatment. Telomerase activity was higher in the depressed patients than in the control subjects.

DISEASE

Mutations in genes offer clues on ALS

Stanford researchers have found mutations in several genes that may be associated with the insurable neurodegenerative disease amyotrophic lateral sclerosis, or ALS.

Scientists examined the DNA sequences of 47 ALS patients who had what's known as the sporadic form of the disease, meaning they had no family history of ALS. The vast majority of patients - up to 90 percent - have sporadic, also referred to as spontaneous, ALS.

Concentrating on a portion of the genome known as the exome, researchers were able to identify 25 new mutations in the patients. Of these, five were mutations in genes that convey messages to chromatin regulators, which are proteins that control how DNA is packed into the nucleus of the cell.

ALS is a progressive, fatal condition in which the motor neurons that control movement and breathing gradually stop functioning. At least one mutated protein they identified in these chromatin regulatory groups has been associated with the ability of the neurons to form the branching structures that are essential to nerve signaling and may contribute to the development of the disease.

Researchers noted that much more work is needed to prove whether the mutations identified could contribute to causing sporadic ALS, but they said it offers ideas of where to look in other patients.

The research was published online Sunday in the journal Nature Neuroscience.

The UC Davis researchers, along with two community groups that serve refugees, interviewed 34 Iraqi men and women who lived in the Sacramento area from December 2008 to August 2012 about their health and any problems they had accessing physical and mental health care services.

In the survey, 79 percent of the refugees reported trauma as the major health concern, followed by 59 percent who named insomnia and 44 percent who reported depression.

The refugees said the U.S. health system was too costly and difficult to understand or use. The majority did not use mental health services because they didn't understand the options or had language difficulties or an unwillingness to broach the topic.

The institute also announced a grant of $6.37 million to Richmond's Sangamo BioSciences to help research therapies for beta-thalassemia, which restricts blood cells' capacity to transport oxygen around the body.

PATHOLOGY

System tracks cancer cells

A new technique invented by Stanford researchers is allowing scientists to take a peek at how different kinds of cells interact and to monitor cancer cell movements in mice.

Scientists have long been able to see cell interaction in living things using microscopes, but the new technique goes a step further, enabling doctors to track where metastatic cancer cells go when they escape from an original tumor site.

Researchers genetically altered immune cells and cancer cells to produce different enzymes that produce light when they are close to each other and are triggered by a reagent. Mice with the altered cancer cells were implanted with the tweaked immune cells. The mice were then injected with the reagent.

After a few weeks, the researchers could see where the immune cells approached the cancer cells because those spots were emitting light. They not only saw light coming from the original tumor site, but also from the nose and lower jaw, showing where the cancer cells had migrated.

The technique was described this month in the journal Proceedings of the National Academy of Sciences.